Not able to visualize contact forces

[hermanjakobsen]

Describe the bug
Pressing "C" on the keyboard has no effect on visualization of the contact forces. Whenever I press the key, the menu says that the contact forces are toggled on but the forces are not visualized.

To Reproduce
Press "C" while simulating an arbitrary environment.

Expected behavior
Expected to see visualization of vectors representing contact forces.

Desktop (please complete the following information):

• OS: Ubuntu 20.04
• Python Version 3.8.5
• Mujoco Version 2.0
• mujoco-py version 2.0.2.9

Environment

• output of: echo $LD_LIBRARY_PATH: /usr/lib/cuda/include:/usr/lib/cuda/lib64:/home/hermankj/webots/lib:/home/hermankj/.mujoco/mujoco200/bin:/home/hermankj/.mujoco/mjpro150/bin

• output of: echo $HOME:
  /home/hermankj

• output of: echo $USER:
  hermankj

[krzentner]

It might be helpful in diagnosing this that openai/gym disabled using mujoco 2.0 because contact forces were always zero. It looks like that issue was never fixed in this repo, although this fork claims to fix it.

[TheButlah]

Is a merge request going to be submitted for that fork? Its only a 1 line change. Any reason it couldn't be merged?

[rohanpsingh]

Was anybody able to solve this issue? I am unable to visualize the contact forces even after applying the patch mentioned by @krzentner.
Is moving to mujoco 1.5 the only solution?

[rohanpsingh]

Update: PR #487 is able to visualize contact forces!